If you race in a horsepower-limited class—typical for anyone racing crate motors, spec engines, or small carburetors—finding just a bit more power simply isn’t an option or it’s prohibitively expensive. But quite often many different components between the end of the crankshaft and the tread on the rear tires are still open. If you can find increases in efficiency by cutting friction anywhere along the driveline, that’s equivalent to finding more horsepower in your engine.

2/21Bulldog Rear Ends has been producing live-axle rearends for Sprint Car racing for years, but the company’s CT-1 rear is its new effort to produce a close-tube quick change rear for stock car racing. After a close inspection, we found that it’s packed with some really well thought out features.

That’s not a new concept here at Circle Track. We’re constantly testing lighter oils, new components, and different configurations in order to help you find more success on the racetrack. This article is no different, except this time around we’re thinking big.

Instead of a single component or product, we’ve decided to put together a dream quick change rearend. The lightbulb for this project went off when we were admiring a pair of billet wide-five hubs from Joe’s Racing Products and thinking about all the applications where these components would be a benefit (while trying to keep the drool off).

The original plan was to pick individual components and put them together, beginning with the Joe’s hubs, building a rearend that is as efficient as possible in order to maximize horsepower to the rear tires while also being strong enough to handle the abuse that racers dish out. But that all changed once we found out about a brand-new stock car quick change unit from Diversified Machine’s Bulldog Rear Ends line.

3/21We’re pairing the Bulldog rear with a pair of wide-five hubs from Joe’s Racing Products, in addition to excellent strength, these hubs reduce rolling resistance with an innovative oiled hub design that makes for easy and quick maintenance.

Bulldog Rear Ends has been around for a while, but it has never really made much of an impact in the stock car racing arena. Instead, Bulldog has concentrated on live-axle rearends for Sprint Car racing. It’s been quite successful in the Sprint community and attracted a loyal following, so when we learned Bulldog was hard at work developing a quick change rear for stock car racing, we knew it would be a quality piece. But when a finished unit was revealed and we got a closer look at it, we realized our original plan of piecing together a rearend one part at a time was a bit pointless.

The Bulldog rear—named the CT-1—is a closed-tube quick change that packs a ton of great features into one unit, and we expect it will start showing up on winning race cars on both dirt and asphalt.

In this article we’ll take a closer look at both the billet wide-five hubs from Joe’s and the CT-1 from Bulldog Rear Ends and how they go together. Next month we’ll follow up with a second edition where we mount a set of birdcages, rotors, and brake calipers from Wilwood, and show you a few tips for mounting your completed rearend in your race car.